Analysts say official statements from some of football’s biggest financial backers reveal the extent of corporate concern over the charges of bribes and backhanders.

After Adidas and Visa spoke out at the weekend, FIFA’s two top-tier “partner” sponsors in Asia, Hyundai and Sony, both underlined the importance of an exhaustive enquiry.

“We are confident that FIFA is taking these allegations seriously and that the Investigatory Chamber of the FIFA Ethics Committee will conduct a thorough investigation,” the South Korean carmaker said.

“Hyundai Motor supports football as a sport that brings people together all over the world and firmly believes the World Cup is the ideal platform to fulfil this objective.”

Sony had a similar reaction to the allegations that former Qatari football boss Mohamed bin Hammam paid millions of dollars in bribes to secure support for Qatar’s deeply controversial victory in a 2010 FIFA vote.

“We expect these allegations to be investigated appropriately, and we continue to expect FIFA to adhere to its principles of integrity, ethics and fair play across all aspects of its operations,” the Japanese electronics giant said.

The tone was mild, but FIFA’s corporate backers rarely speak out and the fact that they issued statements at all pointed, analysts said, to the level of concern.

“It reflects worries that the value of (the) World Cup itself could be harmed,” said Munehiko Harada, professor of sports management at Waseda University.

“It’s difficult to see what political moves are taking place behind the scene. But now the corporates have spoken, FIFA will have to respond,” Harada said.

The two Asian conglomerates make up the six FIFA full partners, along with Adidas, Coca-Cola, Emirates and Visa.

Together they account for hundreds of millions of dollars in World Cup revenues.

Adidas said Sunday it was confident that the matter was being dealt with “as a priority,” while Visa said it would continue to monitor the internal FIFA investigation.

FIFA investigator Michael Garcia, a former US federal prosecutor, is to finish his inquiry into the 2018 and 2022 World Cup votes on Tuesday. But his report is not expected until mid-July, when the World Cup finals finish.

British newspaper The Sunday Times has said it has obtained millions of emails, documents and bank transfers showing that bin Hammam paid over $5 million (3.67m euros) to win support in the bidding process.

The Qatar 2022 Supreme Committee for Delivery and Legacy insists that it won the bid “on its merits”.

A spokesman for another major World Cup sponsor in Asia, Yingli Solar of China, said it had no immediate comment on the corruption allegations.